It is known to have systems for separating fluids from other materials such as the separation of metal chips from lubricating oil which are generated in the course of machining operation on a lathe, mill, etc. One system known in the art is disclosed in U.S. Pat. No. 4,310,417. The '417 patent is directed to a system for separating heavy metal parts prior to the entry of metal chips and oil into a centrifuge separator where the oil is separated from the relatively light metal chips.
While the materials separation system disclosed in the '417 patent is satisfactory in many applications, it has been found deficient in certain applications. In some instances, heavy metal pieces, bars and relatively long pieces of metal such as bar stock do not separate from the lighter metal chips, but instead, are carried to the centrifugal separator where damage occurs to the machine's blades or other parts of the centrifuge.
In operation, the prior art separation system of the '417 patent generally feeds materials to be separated down an inclined chute. A blast of air is pulled upward through an opening in the bottom wall of the chute to provide a vehicle for separating materials in the chute. The air serves to entrain and separate lighter materials from heavier materials and the heavier, undesired materials fall out the drop-out opening.
Unfortunately, the blast of air, which is either blown or pulled into the drop-out opening, is not always satisfactory to provide the desired entrainment and consequent separation. As a result, proper separation does not occur and heavy scrap materials pass into the centrifuge separator. It is believed the separation in the system provided in the '417 patent occurs against gravity, that is, a column of air enters the drop-out opening in the bottom wall of a chute and directs the material to be separated vertically upward--against gravity. If the column of air is not satisfactory for whatever reason, proper separation does not occur.
Another disadvantage sometimes found with the system of the '417 patent is that the material separation occurs in a closed chute such that one cannot view material separation as it occurs. It is not until a problem arises that one is able to deduce that proper separation at a particular location has not occurred; and, by the time it is discovered, damage has already been done to the centrifuge. Moreover, it is difficult to ascertain the requisite air needed for a particular separator application inasmuch as the separation cannot easily be viewed by an operator. As a result, it often takes an inordinate amount of time to insure proper separation.
Other separator devices are available. One is a device disclosed in Fern U.S. Pat. No. 773,556. Coal, bone and rock travel down an open, inclined chute. Prior to material reaching the discharge end of the chute, the material passes over a hinged retarding plate which impedes or retards the movement of the softer foreign substances and reduces its momentum. A blower for buoying the material discharged from the chute is secured to the moveable retarding plate. Accordingly, material passing down the open chute is slowed and allowed to drop off the edge of the chute where it contacts blown air. The material separates and the coal, bone and rock pass to various open chutes. This system slows material prior to discharge from the feed chute, which is disadvantageous. Rather, it is desired that material gain momentum as it approaches the discharge so that the material utilizes the momentum as it approaches a material drop-out opening.
It is important to have the generation of a positive or negative air flow for a system not only to assist the separation of materials in an open area, but also to assist in carrying separated, entrained chips and fluid along the length of a closed chute to a centrifugal separator device.
What is desired is to have a materials separation system in which improved separation occurs by obviating problems that presently exist. One desire is to have a parts separation system in which the parts to be separated are not required to act against the force of gravity in separation, but, rather, gravity is utilized to assist in the separation of materials. Further, it is desired to have a parts separation system in which an operator is able to view the separation of materials prior to entry of the separated materials into a chute member which leads or connects to a machine such as a centrifuge separator.
Further, it is desired to have a system in which material separation is carried out in multiple stages such that several opportunities exist to remove undesired materials from the system. Finally, it is desired to have a multiple-stage separation system in which the separation device is not an entirely closed device, but, rather, the device is open whereby an operator can view each separation phase as it occurs which affords a better opportunity to control and adjust the material separation procedure.